BULLETIN 


OF T HE 

illiNOIS STATE LABO RATORY 

OF 

NATURAL HISTORY 


lJRBA\''-\, ILLl:-iOIS, U. S. A. 

\' OL. VIT. DECE)fBER, 1905. A_RTlCLE V. 

;';OTE::> 0"" SPECIES OF NORTH AMERICAN OLIGOOH ,ETA . Y. THE 

~Y~TE)[ATIO HELA'rIOt-.'SHIPS OF L{.MBRICULUS ( THINODRILUS) IN­

("II;';ST.\ :\'8 (S}IITH ) . 

BY 

FRANK SMITH, A. M., 

A."sis tant Professor of Zoology, University of Illinoi :- _ 

D EC E.\IBER 26, 1905­



ERRATA AND ADDENDA.

Page 35, line 15, for 1854- read 1855.

Page 55, line 16, for Horticultural read State Agricultural.

Page 60, in second table, Illinois, for 240 read 241.

Page 65, first line above foot-note, for ventricosa read ligamentina.

Page 72, line 9, for imhecilis read imbecillis.

Page 79, line 19, for asperimus read asperrimtts.

Page 80, above Quadrula rubiginosa insert Section Fusconaia Simpson.
Page 76. The record of Calkins for Margaritana margaritifera is without

doubt erroneous and should be eliminated. This species is not found in Illinois.

Page 95. Pomatiopsis sheldonii Pilsbry should read Amnicola sheldonii and
should be transferred to the genus Amnicola on page 93.

Page 100. Physa gyrina oleacea Tryon is the immature stage of Physa gyrina.

Page 103. Lymncsa tazewelliana is a synonym of Lymncea parva.

Page 105. Lymncea palustris michiganensis is the immature form of Lymncca
rcflcxa.

Page 106. Lymncza reflexa ioivensis and Lymncea reflexa crystalensis are

synonyms of Lymncea reflexa.

Page 112, line 6 from bottom, for goitldi read gouldii.

Page 114, line 5 from bottom, for jnxtigcns read juxtidens.

Page 115, line 21, for Witter read Walker; line 23, Polygyra sayii Binney should
be changed to Polygyra sayana Pilsbry.

Page 116, line 1. Polygyra exolcta Binney (1885) should be changed to

Polygyra zaleta Binney (1837).

Page 117, line 11 from bottom, for Icai read leaii; line 3 from bottom, Poly-
gyra monodon fraterna is a good species and should read Polygyra fraterna.

Page 119, foot-note. A specimen of alliarins in the collection of Mr. Aldrich,

received from Calkins, proves to be draparnaldi.

Page 121, line 3 from bottom, for Champaign read Piatt.

Page 122, line 12 from bottom, for Pyramidula siriatella Anthony read Pyra-
midiila cronkkitci anthonyi Pilsbry; line 4, for Held read Hald.

Page 123, for Helicodiscus lineatus Say read Hclicodiscus parallcliis Say.

Page 162, line 7, for glandulosa read linearis.

Page 171, line 17, for riparia read vulpina.

Page 176, line 8 from bottom, for canadense read majiis.

Page 180, line 9, for virginica read virginiana.

Page 221, line 6 from bottom, for rectangiiliis read rcctangttlaris.

Page 226, line 3, for fasciatus read fasciata.

Page 239, line 11, strike out Lake Co. entry.

Page 246, lines 6 and 7, and page 248, lines 1, 14, 20, and 23, for CEnothera
read Onagra.

Page 248, line 4, for Candida Horn substitute n. sp.



Pac^e 249, line 8 from bottom, for Olethreutes dimidiana Sodoff? read

Olethreutes separatana Kearfott, and strike out parenthetical matter.

Page 251, line 7, for grossa read thoracica; line 21, for words preceding H. 6,

read Asilus rufipennis Hine; line 18 from bottom, for words preceding H. 2, substi-

tute Asilus cacopilogus Hine.

Page 253, line 8, for Linn, read Emory.

Page 257, line 15, for pennsylvanicus DeG. read auricomus Rob.

Page 261, Note 6. Melanoplus macneilli is very probably M. ftuviatilis Brun.

Page 262, Note 9. Dr. Bergroth writes that Nabis elongatus is preoccupied.

The original is elogantus in the check list. Comparison with long-winged vicarius

is desirable before re-naming it.

Page 309, in table, for 59 read 57, and for 743 read 741.

Page 310, in table, for JS* read 57.

Page 314, line 5, for 1587 read 481; line 16, after stubble insert meadows; line

17, after pastures strike out and meadows, and after 1600 strike out each.

Page 315, last line, for 553 read 481.

Page 362, line 7 from bottom, for longa read parvilamellata.

Page 373. As a second entry in synonymy insert as follows:

1854. Nothrus bistriatus, Nicolet, Acariens des Environs de Paris, p. 397,

PI. VII., Fig. 7.

Page 376, line 13 from bottom, for Oribata read Oribates.

Page 378, line 1, for XXV. read XXXV.
Page 384, after line 5 insert as follows:

N. bipilis Hermann. Mem. Apt., p. 95.

In moss. Areola and Parker, 111.

Page 384, line 5 from bottom, for pyrostigma read pyrostigmata.

Page 386, after line 11 from bottom insert as follows:

H. bistriata Nicolet. Acariens des Environs de Paris, p. 397, PL VII.,

Fig. 7.

Under logs and in moss, Urbana and Areola, 111.

Page 388, line 12, for sphcerulum read sphcsrida.



Article V.

—

Nofes on Species ofNorth American Oligochceta. V.

The Sijsteniafic Relafionships of Liimhriculiis (Thinodrilus)

incoustaus (Smith). By Frank Smith.

When this species was described by the writer (1895) it

was thought that the differences between it and previously

described species were such as to warrant the recognition of a

new genus; hence the genus Thinodrilus. Michaelsen in his

great work on the Oligochida (1900) saw fit to include this species

in the genus Trichodrilus Claparede with the two European
species. Recent papers on the reproductive organs of Lumhric-

iih(s variegafus (Miiller) by Wenig (1902) and Hesse (1902)

have extended our knowledge of that species and have shown
that it is in some particulars very similar to Thinodrilus in-

consfans, and as it now seems to the writer that there is more rea-

son for including the latter species in the genus Lnmhriculus

than in the genus Trichodrilus, it will be referred to in the fol-

lowing discussion as Lumhriculus inconsfans.

We will first consider the chief points in which L. inconsfans

differs more from L. rariegatus than from the two species of Tri-

chodrilus {T. allobroguniC\-dii'dYedeQ.nd T. pragensisYejdovsky).

Albumen Gland.—An albumen orcopulatory gland, which

is described and figured by Vejdovsky (1884) as occurring in

somite IX in L. variegatus, is lacking in Trichodrilus and in L.

inconstans. No reference is made to such an organ by Wenig
and Hesse in their recent papers on L. rariegatus, and Michael-

sen (1903, p. 60) has recently raised the question as to its oc-

currence, and queries whether the structures seen by Vejdov-

sky may not have been rudiments of efferent reproductive

organs. It should not be overlooked that the structure of the

albumen gland is described by Vejdovsky (1884, p. 149) as simi-

lar to that of the spermathecte, and that Wenig (1902) de-

scribes and figures a single spermatheca in IX but makes no

reference to an albumen gland. Vejdovsky used the presence



46

or absence of an albumen gland as the basis for the separation

of the Lumbriculidce into two groups, but without presenting

any reason for believing that such a character should be con-

sidered of especial importance in determining systematic rela-

tionships, and I am disposed to assume that it has at the most
no greater significance than that of a specific character.

Positions of Spermidiical Pores and Gonads.—The spermidu-

cal pores are usually on VIII in L. variegatus, but Vejdovsky

(1895) found them on VII in one specimen. Wenig found but

one spermiducal pore in each of the specimens examined by
him, and that on VIII. In L. inconsfa)is the spermiducal pores

are on X in two of the specimens studied and on XI in another.

In the two species of Trichodrilus they are on X. With such
individual variability in mind, it seems reasonable to consider

the position of the spermiducal pores as of no more than spe-

cific importance. In L. variegatus there is one pair of testes and
one pair of spermiducal funnels in VIII, and there are two pairs

of ovaries in IX and X. In L. ijtconstaus there are two pairs of

testes and two pairs of spermiducal funnels in IX and X, and
two pairs of ovaries in XI and XII. In the European species

of Trichodrilus there is uncertainty about the testes. There are
two pairs of spermiducal funnels in IX and X and one pair
of ovaries in XI. With reference to the position of the gonads
our species is nearer to Trichodrilus, while in respect to the
number of ovaries it is more like L. variegatus.

We will next consider several important respects in which
L. inconstans more closely resembles L. variegatus than it does
the European species of Trichodrilus.

Setce.—ln L. variegatus and L. inconstans the setae are cleft;

in Trichodrilus they are simple. While it is true that in some
lumbriculid species the setse may be partly simple and partly
cleft, yet to my- knowledge there has been no occasion for
placing in the same genus species with setae all simple and
other species with set* all cleft, except in the genus Tricho-
drilus as defined by Michaelsen (1900, p. 58) in order that it

might include the species inconstans.



47

Vascular System.—InL. varier/afiis a pair of transverse vessels

connects the -dorsal and ventral vessels in each of several

anterior somites. They are situated just anterior to the septum.

They are small in somites back of XX, and are so close to the

wall of the intestine and so covered by chloragogue cells that

they are seldom recognizable. A single pair of cseciform,

contractile, branched vessels, connected only with the dorsal

vessel, is contained in the anterior part of each somite posterior

to XV (Ratzel, 1868), and, according to Dieffenbach (1886),

smaller ones are found as far forward as IX. The description

of the circulatory system of L. i}icoHsfans in my earlier treat-

ment of that species (1895) was very incomplete and did not

give enough data for comparisons, but as far as transverse

vessels are concerned the conditions existing in that species

and in L. variegatns are closely similar. In L. incoiistans the

paired vessels which connect the dorsal and ventral vessels,

in the posterior part of each somite, are recognized with dif-

ficulty posterior to XVII, and the ctecal branches of the dorsal

first appear in XI and then occur regulady, there being one

pair, and only one, in each somite. In each of the two

species of Trichodrllus, in the middle region of the body there

are four or more ctecal branches of the dorsal vessel on each

side in each somite, instead of a single one as in each species

of Lumhriciilus.

Spermathecce.—In L. rariegatus there is much variability

in the position and arrangement of the spermathecce. Vejdovsky

reported three pairs in X—XII; Hesse found four pairs in

X—XIII; and Wenig found them more or less asymmetrically

distributed in IX—XV. In L. incotistans I have found five

pairs in XI--XV or in XII—XVI. In Trichodrilns but one or

two pairs are found, and these are in XI or in XI and XII.

The spermathecal pores of both species of Liouhriculns are at

least as high up on the sides as the ends of the transverse

diameter, while the pores of both species of Tricliody'dus are

described as behind the ventral setae.



48

Atrium and Penis.—Yejdowsky (1895) describes and figures

the atrium and penis of L. variegatus. Hesse did not at first

( 1894) recognize the presence of thepenis, but later (1902) reex-

amined his preparations and found it to be present. Wenig

confirmed the observations of Vejdovsky. In my former de-

scription of L. inconsfans the following statement occurs:

"Whether or not a definite penis is developed I am unable to

state." A reexamination of my specimens has revealed the

presence of a penis, formerly overlooked because of its great

transparency. This organ and the atrium are both very simi-

lar to those of L. variegatus.

Besides these more important characters in which L. incon-

sfffM^ resembles L. variegatus much more closely than it does

the species of Trichodrilus, there are others of less importance,

but nevertheless significant, in which the two former species are

closely similar. (1) They are both greenish anteriorly. (2)

The usual number of somites in each is more than double, the

number in the two species of Trichodrilus. (3) They are no-

ticeably similar in the extreme infrequency with which sexu-

ally mature specimens are found. I have examined hundreds

of specimens of L. inconstans, taken at various times of the

year, and have found but three with reproductive organs de-

veloped. (4) The form of the brain is quite similar in the two

species of Lmnhriculus and quite different from that of Tricho-

drilus pragensis as described and figured by Vejdovsky (1876).

(5) In both species of Lumhriculus nephridia are found in the

same somite as are the genital dacts, which is not the case in

Trichodrilus. (6) The sperm-sacs in both species oi Lumhricu-

lus extend posteriorly from the atrial somite through a consid-

erable number of somites, while in Trichodrilus pragensis sperm-

sacs are apparently formed anterior to the atrial segment as

well as posterior to it (Vejdovsky, 1876, p. 548, Fig. 2).

If we follow somewhat closely the general type of generic

and specific definitions adopted by Michaelsen (1900), we may
define Lumhriculus and its two species in the following terms.



49

Liimhrkiilus Grube.

Prostomin 111 rounded. Seta^ cleft. One pair of spermidu-
cal pores. Two pairs of oviducal pores. Tliree pairs, or more,
of spermathecal pores, open laterally on some of somites IX

—

XVI. Dorsal and ventral vessels connected in posterior part

of each somite by a pair of transverse vessels; the dorsal vessel

in each somite with one pair of contractile caecal transverse ap-

pendages except in a few anterior somites. Sperm-ducts open
into a single atrium or pair of atria provided with protrusible

penis. Two pairs of ovaries and of oviducal funnels. Sperma-
thecEE simple; three pairs or more in somites posterior to atria.

Li(iuhriei(h(s variegatus (0. F. Miiller).

In life reddish to dark brown, anteriorly greenish. Pros-

tomium rounded conical, length li times the basal width, with

"head" pore at the apex. Spermiducal pores on VIII (excep-

tionally on Vlt), posterior to ventral setae. Two pairs of

oviducal pores, IX/X and X/XI. Spermathecal pores on some
of somites IX—-XV, sometimes asymmetrically distributed.

Brain anteriorly slightly concave, posteriorly with a deep,

rounded trilateral incision. Transverse vessels of I—VIII much
branched, forming a connected vascular plexus, the following

ones simple; contractile caecal transverse appendages of the

dorsal vessel beginning in IX, at first short and simple but

becoming longer and branched in succeeding somites. One
pair of testes and one pair of spermiducal funnels in VIII.

Atria pyriform, one pair in VIII (exceptionally in VII), or

single. Two pairs of ovaries and of oviducal funnels in IX
and X. Spermathecae simple, three pairs or more in some of

somites IX—XV, sometimes asymmetrically distributed.

An unpaired copulatory (albumen) gland in IX. (?) Length,

40—80 mm. Diameter, 1—1.5 mm. Number of somites, 140

—

200, or more.



50

Lumhricidus inconstans (Smith).

In life reddish, anteriorly greenish. Prostoraium rounded,

length litimes the basal width. Spermiducal pores on X (excep-

tionally on XI). Two pairs of oviducal pores, XI/XII and

Xll/Xill. Spermathecal pores on XI—XV or XII—XVI. Brain

anteriorly, but slightly, concave, posteriorly with a deep, round-

ed trilateral incision. Contractile csecal transverse appendages

of the dorsal vessel beginning in XI, becoming larger and more
branched in succeeding somites. Two pairs of testes and two
pairs of spermiducal funnels in IX and X. Atria pyriform,

one pair in X (exceptionally in XI). Two pairs of ovaries and

two pairs of oviducal funnels in XI and XII. Five pairs of

spermathecseinXI—XV or XII—XVI. Nocopulatory (albumen)

gland. Length, 30—60 mm. Diameter, .6—.8 mm. Number of

somites, 150—200, or more.

If the above disposition of the two species under discussion

be correct, and if the views of Micbaelsen (1902) concerning

the phylogenetic relationships of the lumbriculid genera are

well founded, the species 'uiconstans seems to have the more
primitive condition of spermiducal structures, and L. variegatus

may have been derived from it by the disappearance of the ante-

rior pair of testes and of sperm-ducts and a reduction in the num-
ber of anterior somites. The specimen of L. inconstans referred

to above, in which the spermiducal pores are on a somite pos-

terior to the somites containing the testes, presents a condi-

tion normal to families higher than the Lumbriculid(e but not

ordinarily found in that family.

The transfer of the American species from the genus
Trichodrilus to Lumhriculus leaves the former genus much
more homogeneous and simplifies its definition.

University of Illinois, December 16, 1905.



LITERATURE CITED.

Dieffenbach, O.

1886. Anatomische und systeniatische Studieii an Oligochaetae

limicolae. Ber. oberhess. Gesellsch. f. Natur- u. Heilkunde,
Bd. XXIV., pp. 65-108, Taf. II.

Hesse, R.

1894. Die Geschlechtsorgane von Lumbriculus variegatus

Grube. Zeit. f. wiss. ZooL, Bd. LVIII., pp. 355-362, Taf.

XXII.
1902. Zur Kenntnis der Geschlechtsorgane von Lumbriculus

variegatus Zool. Anz., Bd. XXV., pp. 620-622.

Michaelsen, W.
1900. Oligochaeta. Das Tierreich, Lief. 10, pp. I-XXIX,

1-575.

1902. Die Oligochaeten-Fauna des Baikal-Sees. Verb. nat.

Ver. Hamburg (3), Bd. IX., pp. 43-60. 1 fig.

1903. Die geographische Verbreitung der Oligochaeten. 186

pp., 10 Kart. Berlin.

Ratzel, F.

1869. Beitrage zur anatomischen und systematischen Kennt-
niss der Oligochaeten. Zeit. f. wiss. Zool., Bd. XVIIL, pp.

563-591, Taf. XLII.

5mith, F.

1895. Notes on Species of North American 01igocha3ta. Bull.

111. State Lab. Nat. Hist., Vol. IV., pp. 285-297.

Vejdovsky, F.

1876. Ueber Phreatothrix, eine neue Gattung der Limicolen.

Zeit. f. wiss. Zool., Bd. XXVII., pp. 541-554, Taf. XXXIX.
1884. System und Morphologie der Oligochaeten, pp. 1-166,

Taf. I-XVI.
1895. Zur Kenntnis des Geschlechtsapparates von Lumbriculus

variegatus. Zeit. f. wiss. Zool., Bd. LIX., pp. 80-82.

Wenig, J.

1902. Beitrage zur Kenntnis der Geshlechtsorgane von Lum-
briculus variegatus Grube. Sitzungsber. d. Konigl. bohm.

Ges. d. Wiss., 1902. 11 pp., 1 Taf.